Focal Adhesion Protein-Tyrosine Kinases ; Humans ; Liver Diseases, Alcoholic ; enzymology ; pathology

Resistance to the induction of apoptosis is a possible mechanism by which tumor cells can survive anti-neoplastic treatments. Melanoma is notoriously resistant to anti-neoplastic therapy. Previous studies have demonstrated focal adhesion kinase (FAK) overexpression in melanoma cell lines. Given its probable role in mediating resistance to apoptosis, many researchers have sought to determine whether the downregulation of FAK in melanoma cells would confer a greater sensitivity to anti-neoplastic agents. Genistein is a known inhibitor of protein-tyrosine kinase (PTK), which may attenuate the growth of cancer cells by inhibiting the PTK-mediated signaling pathway. This present study was undertaken to investigate the effect of genistein on the expression of FAK and cell cycle related proteins in the G361 melanoma cell line. Genistein was found to have a preferential cytotoxic effect on G361 melanoma cells over HaCaT normal keratinocytes. Genistein decreased the expression of 125 kDa phosphotyrosine kinase and the FAK protein in particular. Genistein treatment did not affect the expression of p53 in G361 cells in which p21 is upregulated. The expression of cyclin B and cdc2 was downregulated by genistein treatment. Taken together, our data indicate that genistein induces the decreased proliferation of G361 melanoma cells via the inhibition of FAK expression and regulation of cell cycle genes. This suggests that the use of genistein may be a viable approach to future melanoma treatments.
Apoptosis ; Cell Cycle ; Cell Line ; Cyclin B ; Down-Regulation ; Focal Adhesion Protein-Tyrosine Kinases ; Focal Adhesions ; Genes, cdc ; Genistein ; Keratinocytes ; Melanoma ; Negotiating ; Phosphotransferases ; Phosphotyrosine ; Protein-Tyrosine Kinases ; Proteins

Cell Adhesion ; drug effects ; Cell Movement ; drug effects ; Focal Adhesion Kinase 1 ; genetics ; metabolism ; Focal Adhesion Protein-Tyrosine Kinases ; Neoplasms ; Phosphorylation

BACKGROUND: Epstein Barr virus (EBV) infected B cells are transformed into lymphoblastoid cell lines. Some researchers suggested some a few similarities between this process and carcinogenesis. We observed the expression of CD80 and CD86, co-stimulatory molecules on EBV-transformed B cells and changes of CD54 expression after stimulation of CD80 and CD86. METHODS: CD80 and CD86 were stimulated using anti-CD80 and anti-CD86 monoclonal antibodies. To assess apoptosis and surface protein expression, flow cytometric analysis was performed. Intracellular signal molecules were evaluated by RT-PCR and immunoblot. Morphology and localization of proteins were examined using inverted or confocal microscope. RESULTS: Cross-linking of CD80 and CD86 induced apoptosis and interfered with proliferation of EBV-transformed B cells, and dispersion of clumped cells. We also examined that their stimulation induced ROS accumulation and reduced CD54 expression. Interestingly, we observed that CD80 and CD86 diminished the expression of CD54 in different methods. Both CD80 and CD86 down-regulated activation of focal adhesion kinase. CD80 stimulus inhibited CD54 expression through mainly RhoA inactivation, while CD86 down-regulated Ras and JNK phosphorylation. CONCLUSION: These results suggest that co-stimulatory CD80 and CD86 molecules, expressed EBV-transformed B cells, may play a role in apoptosis and cell adhesion.
Antibodies, Monoclonal ; Apoptosis ; B-Lymphocytes ; Cell Adhesion ; Cell Line ; Focal Adhesion Protein-Tyrosine Kinases ; Herpesvirus 4, Human ; Proteins

PURPOSE: We propose that cell attachment can be regulated by the modulation of FAK expression using an adenovirus vector. MATERIALS AND METHODS: Chondrocytes and chondroid cells were used in cell attachment test by blocking or non-blocking of antibodies and synthetic peptides on type II collagen precoated 96-well immunoplates. The C-terminal domain of FAK(FAK-CD) was transfected through infection of the recombinant adenovirus. Also tyrosine phosphorylation of FAK was checked by immunoprecipitation of FAK followed by western blot analysis with anti-phosphotyrosine antibody. For evaluating the change of integrin expression, semi-quantitative reverse-transcription polymerase chain(RT-PCR) reactions were done after transfection of FAK-CD. RESULTS: We observed more increased expression of FAK in the chondroid cells than that in chondrocytes using western blotting. The level of attachment to type II collagen was significantly inhibited by blocking with the monoclonal antibody of integrin-beta1 and synthetic RGD peptides. Also adenovirus mediated transfection of FAK-CD resulted in inhibition of phosphorylation of FAK and significantly inhibited cell attachment in only JJ102. Integrin-beta1 antibody blocking after transfection with FAK-CD showed inhibition of cell attachment in more than 95% of all cells. The mRNA expression of both Integrin a2 and integrin a5 was increased but was not significant. Protein expression of integrin a2 and integrin a5 showed no changes. CONCLUSION: We found that the attachment of FAK-overexpressing cells could be mediated through integrin-beta1 receptor. We concluded that the modification of FAK expression will contribute to increase the cell attachment to biomaterials and regeneration of cartilage defects.
Adenoviridae ; Adhesiveness* ; Antibodies ; Biocompatible Materials ; Blotting, Western ; Cartilage ; Chondrocytes ; Collagen Type II ; Focal Adhesion Protein-Tyrosine Kinases ; Focal Adhesions* ; Immunoprecipitation ; Peptides ; Phosphorylation ; Regeneration ; RNA, Messenger ; Transfection ; Tyrosine

PURPOSE: We propose that cell attachment and invasion can be regulated by the modulation of FAK expression in chondrosarcoma cell lines. MATERIALS AND METHODS: The C-terminal domain of FAK (FAK-CD) was transfected by recombinant adenovirus infection in chondrosarcoma cell lines, JJ012 and 105KC. The expression of FAK, FAK-CD and tyrosine phosphorylation were checked. Chondrocytes and chondrosarcoma cells were used in cell attachment tests by blocking or not blocking integrin-beta 1 antibodies and synthetic peptides on type II collagen. To evaluate the effect of cell invasiveness, a wound healing assay and a Boyden chamber assay were done after FAKCD transfection. RESULTS: We observed higher FAK expression in the chondrosarcoma cells than in chondrocytes. The level of attachment to type II collagen was significantly inhibited by blocking with the antibody of integrin-beta 1 and synthetic RGD peptides. Also, the adenovirus mediated transfection of FAK-CD resulted in the inhibition of the phosphorylation of FAK and significant inhibition of cell attachment in only JJ012, without changing FAK expression. Moreover, migration after transfection with FAK-CD was reduced by up to 79.9% for JJ012 and 75.5% for 105KC. CONCLUSION: Attachment of chondrosarcoma cells could be mediated through integrin-beta 1. We conclude that modified FAK expression contributes to the suppression of tumor cell attachment and invasion.
Adenoviridae ; Adenoviridae Infections ; Antibodies ; Cell Line* ; Chondrocytes ; Chondrosarcoma* ; Collagen Type II ; Focal Adhesion Protein-Tyrosine Kinases* ; Focal Adhesions* ; Peptides ; Phosphorylation ; Transfection ; Tyrosine ; Wound Healing

Synaptic plasticity has been thought to be a mechanism of synaptic maturation, learning and memory. In this study, the possible involvement of Rac, RhoA, proline-rich tyrosine kinase 2 (PYK2) and focal adhesion kinase (FAK) in the synaptic plasticity was investigated using PC12 cells and rat brains. The followings are the results. 1. Depolarization induced extracellular signal-regulated kinase (ERK) activation but did not activate Rac and RhoA in PC12 cells. 2. ERK activation and c-fos expression were observed after electroconvulsive shock (ECS) but the activity of Rac and RhoA was not changed following ECS. 3. PYK2 not FAK activation was observed after ECS. 4. The activity of PYK2 was increased with postnatal development but that of FAK was decreased with ages. 5. The expression of Rac and PYK2 was clearly observed in the postsynaptic density but that of RhoA and FAK was not. These findings indicate that PYK2 seems to play an important role in activity-dependent synaptic plasticity in vivo brain.
Animals ; Brain ; Electroshock ; Focal Adhesion Kinase 2 ; Focal Adhesion Protein-Tyrosine Kinases ; GTP Phosphohydrolases* ; Learning ; Memory ; Nervous System* ; PC12 Cells ; Phosphotransferases ; Plastics ; Post-Synaptic Density ; Rats ; Signal Transduction*

Mutation of leucine-rich repeat kinase 2 (LRRK2) causes an autosomal dominant and late-onset familial Parkinson's disease (PD). Recently, we reported that LRRK2 directly binds to and phosphorylates the threonine 474 (T474)-containing Thr-X-Arg(Lys) (TXR) motif of focal adhesion kinase (FAK), thereby inhibiting the phosphorylation of FAK at tyrosine (Y) 397 residue (pY397-FAK), which is a marker of its activation. Mechanistically, however, it remained unclear how T474-FAK phosphorylation suppressed FAK activation. Here, we report that T474-FAK phosphorylation could inhibit FAK activation via at least two different mechanisms. First, T474 phosphorylation appears to induce a conformational change of FAK, enabling its N-terminal FERM domain to autoinhibit Y397 phosphorylation. This is supported by the observation that the levels of pY397-FAK were increased by deletion of the FERM domain and/or mutation of the FERM domain to prevent its interaction with the kinase domain of FAK. Second, pT474-FAK appears to recruit SHP-2, which is a phosphatase responsible for dephosphorylating pY397-FAK. We found that mutation of T474 into glutamate (T474E-FAK) to mimic phosphorylation induced more strong interaction with SHP-2 than WT-FAK, and that pharmacological inhibition of SHP-2 with NSC-87877 rescued the level of pY397 in HEK293T cells. These results collectively show that LRRK2 suppresses FAK activation through diverse mechanisms that include the promotion of autoinhibition and/or the recruitment of phosphatases, such as SHP-2.
Focal Adhesion Protein-Tyrosine Kinases ; Glutamic Acid ; Parkinson Disease ; Phosphoric Monoester Hydrolases ; Phosphorylation ; Phosphotransferases ; Protein Tyrosine Phosphatase, Non-Receptor Type 11* ; Threonine ; Tyrosine*

Cell migration plays an important role in repair of injury, angiogenesis, cancer metastasis and so on. In this paper the effects of basic fibroblast growth factor (bFGF) of different concentrations on ECV-304 cell migration, and the dynamic changes in focal adhesion kinase (FAK) were observed. The relationship between FAK and cell migration induced by bFGF was studied. A ECV-304 cell scratch wound model was established and the images of cell migration were quantitatively measured using a computer-assisted videomicroscopic system. The dynamic changes in FAK content (Western blot), FAK activity (immunoprecipitation plus Western blot) and FAK mRNA (RT-PCR) were measured in vitro. The expression of integrin alpha3 was investigated using immunocytochemical staining (ABC method). The results showed that bFGF produced a dual-phase regulatory effect on ECV-304 migration when the cell confluent areas reached 90%-95% in culture. It was found that compared with the control group (0 ng/ml bFGF), the cell migration was stimulated (P<0.05), inhibited (P<0.05) and unchanged when the cultured cells were treated with bFGF at the concentrations of 5, 10 and 15 ng/ml, respectively. The content and activity of FAK protein were markedly up-regulated in 5 ng/ml bFGF group and down-regulated in 15 ng/ml bFGF group, respectively. FAK mRNA expression came to the peak in 5 ng/ml bFGF group after 6 h culture and there was a significant difference compared with the control group. In various experimental groups there were no significant differences in the expression of integrin alpha3 compared with the control group according to the immunocytochemical staining. The results mentioned above suggest that different concentrations of bFGF have a dual-phase effect on the migration of cultured ECV-304 cells, which correlates positively with FAK content, activity and mRNA in cultured ECV-304 cell scratch wound model. The FAK plays an important role in the signal transduction pathway of cell migration induced by bFGF, while bFGF can regulate the content of FAK in ECV-304 cells at gene transcription level.
Cell Movement ; physiology ; Cells, Cultured ; Endothelium, Vascular ; cytology ; Fibroblast Growth Factor 2 ; physiology ; Focal Adhesion Kinase 1 ; Focal Adhesion Protein-Tyrosine Kinases ; Humans ; Integrin alpha3 ; metabolism ; Protein-Tyrosine Kinases ; metabolism ; RNA, Messenger ; metabolism ; Umbilical Veins ; cytology

Animals ; Colonic Neoplasms ; metabolism ; pathology ; Focal Adhesion Kinase 1 ; Focal Adhesion Protein-Tyrosine Kinases ; Humans ; Integrins ; metabolism ; Neoplasm Invasiveness ; Neoplasm Metastasis ; Protein-Tyrosine Kinases ; metabolism ; Rectal Neoplasms ; metabolism ; pathology ; Signal Transduction